1. Field of the Invention
The present invention relates to an electrode assembly which can be used in a cell such as for electroplating. The electrode assembly has an outer metal electrode member which typically is tube-like. The electrode assembly also has an inner metal electrical current distributor member. In cross-section, the current distributor member has edges which bite into the inner face of the hollow electrode member providing electrical junction between the members.
2. Description of the Related Art
It has been known to construct electrodes which are composites of an outer sheath of one metal and an inner core of a differing metal. For example, in U.S. Pat. No. 4,657,652 there is disclosed an electrode having a metal sheath such as of titanium over a supporting core, which can be of copper or aluminum. The titanium sheath is provided to cover the core metal and provide the working surface of the electrode. There can be a strong metallurgical bonding between the metals.
It has also been known to construct electrodes of spaced-apart plates with a core filler. In U.S. Pat. No. 4,460,450 there are disclosed electrodes of electrode plates sandwiching an area between the electrode plates. The area can include wires combined with the use of the core metal filler. The wires are welded to the electrode plates. The patent teaches that zinc can serve as a core metal filler.
It has also been known to form opposing sheets of titanium into an envelope and use a particulate filler. Such a composite electrode has been shown in U.S. Pat. No. 3,907,659. Therein it is taught to utilize two opposing sheets of titanium to form an envelope. Copper wool or shredded copper, in a compressed state, is disposed within the envelope to provide a core of substantially enhanced electrical conductivity, while the titanium sheets protect the copper from chemical corrosion.
It has also been known to prepare a protected electrode structure using a sheath and core structure, where the core is an electrode. Such a structure has been taught in U.S. Pat. No. 4,171,254. The teachings of this patent are directed to a structure where a sacrificial anode is placed in an environment where metal-to-metal impacts are possible and could create dangerous sparking. To prevent against this, the patent teaches shielding the sacrificial anode with an outer perforate shield. The perforate shield will permit ongoing sacrificial action of the inner anode while supplying a protective casing for eliminating contact of the anode with other metal structure.
It would still be desirable to provide an electrode assembly having a core structure which is protected by an outer electrode, not only during use of the electrode, but also during refurbishing of the electrode. Such assembly would, however, need to maintain highly efficient and economical electrical contact between the electrode outer component and the inner core of substantially greater electrical conductivity.